Mini Tutorial Special Variables

(defvar*global-var-1*)(defvar*global-var-2* 42 "With an initial value if it doesn't already have one and a docstring.")(defparameter*global-var-3* 33 "Defparameter always assigns the value to the variables.")

defvar or defparameter have both compilation-time effects and load-time/execution effects. For their compilation-time effects to be visible, they must be written before the functions that use the variables, otherwise the compiler will signal a warning.